1. Field of the Invention
The invention relates to an optical viewer instrument with a photographing function.
2. Description of the Related Art
As is well known, an optical viewer instrument, such as a binocular telescope, a single telescope or the like, is used for watching sports, wild birds, and so on. When using such an optical viewer instrument, it is often the case that the user sees something that he or she would like to photograph. Typically, he or she will fail to photograph the desired scene because he or she must exchange a camera for the optical viewer instrument and during this time the chance is lost. For this reason, an optical viewer instrument containing a camera is proposed, whereby a photograph can be taken immediately by using the camera contained in the optical viewer instrument while continuing the observation through the optical viewer instrument.
For example, Japanese Laid-Open Utility Model Publication (KOKAI) No. 6-2330 discloses a combination of a binocular telescope and a camera, in which the camera is simply mounted on the binocular telescope. Of course, the binocular telescope includes a pair of telescopic lens systems, and the camera includes a photographing lens system. While an object is observed through the pair of telescopic lens systems, the observed object can be photographed by the camera. Also, this binocular telescope with the camera is bulky, and is not so easy to handle, because the camera is simply added to the binocular telescope.
In a case where a digital camera is combined with an optical viewer instrument, it is desirable to incorporate a display panel unit, such as a liquid crystal display (LCD) panel unit, in the optical viewer instrument with the digital camera to monitor an object to be photographed, similar to a conventional digital camera. The location of the display panel unit should be considered, after taking various functions of the optical viewer instrument with the digital camera into consideration. Namely, the display panel unit should be located at a handy position on the optical viewer instrument with the digital camera.
When the optical viewer instrument with the digital camera has the display panel unit, it is necessary to arrange a display selection switch on a casing of the optical viewer instrument with the digital camera to select either a display mode or a non-display mode, similar to a conventional digital camera. Namely, when the display mode is selected by turning ON the display selection switch, an object to be photographed is displayed as a motion picture on the display panel unit. When the non-display mode is selected by turning OFF the display selection switch, the display of the motion picture on the display panel unit is cancelled.
The optical viewer instrument with the digital camera is different from the conventional digital camera in that the former is utilized as a usual viewer instrument, such as a binocular telescope, a single telescope and so on. Therefore, the optical viewer instrument with the digital camera is frequently carried in an exposed manner being uncovered from a cover case, and thus it is often the case that the display selection switch will be inadvertently operated. When the display selection switch is inadvertently turned ON, batteries, loaded in the optical viewer instrument with the digital camera, will unnecessary run down.
Further, there is known another type of binocular telescope containing a camera, in which an objective lens system, included in one of both the telescopic lens systems, is utilized as a part of the photographing lens system.
In particular, each of the telescopic lens systems includes an objective lens system, an erecting prism system, and an ocular lens system. A half mirror is incorporated in one of the telescopic lens systems so as to be disposed between the objective lens system and the erecting prism system to define an angle of 45° with respect to the optical axis of the telescopic lens system concerned. A light beam, made incident on the objective lens system, is divided into two parts by the half mirror. Namely, part of the light beam passes through the half mirror toward the ocular lens system, and the remaining part of the light beam is reflected by the half mirror so as to be introduced in the photographing lens system.
Due to this arrangement, this type of binocular telescope with a camera may be more compact in comparison to the binocular telescope with a camera, disclosed in the Publication (KOKAI) No. 6-2330. Nevertheless, it is disadvantageous in that the amount of the light that is incident on the photographing lens system is diminished.